Nuclear modification of prompt and non-prompt J/Ψ production in p-Pb collisions at √SNN = 5.02 TeV with ALICE

Giuseppe Trombetta

doi:10.1051/epjconf/201819200018

Abstract

Various Cold Nuclear Matter (CNM) effects, such as nuclear shadowing or partonic energy loss, can modify the production of J/Ψ in heavy-ion collisions with respect to what is measured in elementary colliding systems. The study of p-Pb collisions at the Large Hadron Collider (LHC) energy scale represents a crucial tool to assess the influence of Cold Nuclear Matter on J/Ψ production in order to achieve a more correct interpretation of Pb-Pb collision results. The ALICE detector at the LHC is capable of reconstructing J/Ψ mesons at central rapidity through their e+e- decay channel down to zero transverse momentum (pT), and has measured the fraction of J/Ψ produced from the decay of beauty-flavoured hadrons (non-prompt J/Ψ) in p-Pb collisions down to pT = 1:3 GeV/c. In this paper, the results obtained by ALICE from the measurement of the prompt and non-prompt J/Ψ yields at mid-rapidity in p-Pb collisions at √SNN = 5.02 TeV will be discussed in comparison to different theoretical predictions including CNM effects.

Highlights

Quarkonia and open heavy-flavoured hadrons have long been the subject of an intense theoretical and experimental effort
While heavy-quarks are considered as excellent tools for probing the transition of hadronic matter to a Quark–Gluon Plasma (QGP) phase in ultra-relativistic heavy-ion collisions, several mechanisms not related to the formation of QGP, and referred as Cold Nuclear Matter (CNM) effects, can contribute to modify the observed yields with respect to elementary nucleon-nucleon (NN) collisions
For heavy quarks produced at the Large Hadron Collider (LHC), the most relevant are the parton-density shadowing and gluon saturation effects, which can be described using modified nuclear parton distribution functions [1] or in the framework of the Color-Glass Condensate (CGC) effective theory [2]

Summary

Introduction

Quarkonia and open heavy-flavoured hadrons have long been the subject of an intense theoretical and experimental effort. Their production represents a challenging testing ground for models based on quantum chromodynamics (QCD), and several initial- or final-state effects can contribute to modify the yields measured over different colliding systems. While heavy-quarks are considered as excellent tools for probing the transition of hadronic matter to a Quark–Gluon Plasma (QGP) phase in ultra-relativistic heavy-ion collisions, several mechanisms not related to the formation of QGP, and referred as Cold Nuclear Matter (CNM) effects, can contribute to modify the observed yields with respect to elementary nucleon-nucleon (NN) collisions. ALICE has recently reported the measurement of such component [6], allowing an assessment of CNM effects on beauty quark production as well as a more direct comparison with models describing prompt charmonium production in heavy-ion collisions

Data sample and analysis

Results

Summary